1. Field
The invention relates to a device for raising the forefoot in the case of dysfunction of the peroneal nerve by means of an elastic connector having adjustable bias tension means which acts between the forefoot and the lower leg.
2. Physiology Background--Peroneal Nerve Dysfunction
In the healthy human being a trouble-free course of walking or running movement occurs by the alternate raising and lowering of the forefoot. The raising of the forefoot is caused by the muscles and ligaments running in the dorsum of the foot; these are controlled by the peroneal nerve which is part of the autonomous nervous system. When a partial nerve paralysis occurs, such as frequently remains after a stroke or cerebral hemorrhage, or due to injuries consequent to an accident, for example, an interruption of the nerve conduction system, a dysfunction of the peroneal nerve often occurs resulting in neurological failures of the foot-raising muscles and ligaments. In persons handicapped in such a manner, the forefoot constantly hangs downward by reason of its weight. In order to avoid dragging of the toes on the ground and incessant stumbling when advancing the foot during walking or running movement, the knee must be abnormally lifted (steppage). Walking is slow and awkward; running is difficult, if not impossible.
3. Description of Prior Art Devices, Their Disadvantages and Need in the Art
A known device for raising the forefoot shown in Medizinische Klinik, 1955, 155, No. 49, page 2094, has a relatively rigid right-angle plate arranged under the sole of the foot and behind the fibula, which rigidly fixes the foot in its normal position. The fibula-side shank of the angle plate is joined to the lower leg of the handicapped person, for example, by a strap. The sole-side plate shank is worked into an orthopedic shoe inlay or directly into an orthopedic shoe.
This device has a number of disadvantages. Because the angle plate is relatively rigid, the foot is unchangeably fixed in a right-angled position. The lowering of the foot, which is still possible in the case of a dysfunction of the peroneal nerve, is severly hampered by this device, and thus unimpeded extension of the foot is impossible.
A further drawback of this device is that the handicappted person must exclusively use orthopedic shoes since the angle plate, due to its awkward dimensions, is impossible to be received in a normal shoe. Thus, the handicapped person cannot wear sandals or slippers, for example, in domestic surroundings, without unhampered movement.
Finally, this device is highly disadvantageous in cosmetic respects, since the orthopedic shoe modified with the right-angle plate appears antiquated and clumsy. That shoe contrasts sharply with a normal shoe worn on the other healthy foot. Moreover, it is uncomfortable to wear as a consequence of its great weight.
German Pat. No. 349,372 shows another known practice in which a boot is adapted with an elastic connection between the part surrounding the forefoot and the shaft enclosing the lower leg. The elastic connection consists of a strap and a rubber band, in which arrangement the bias tension by which the forefoot is raised is adjustable. This arrangement, too, has the disadvantage that it offers aid to the injured person only if he is actually wearing the shoe.
Accordingly, there is a clear need in the art for solving the problem of creating a device which is usable without a specially constructed shoe, and which is inconspicuous.